Table 1.
Clinicopathological features of HER2-negative breast cancer stratified by HER2 expression
| All HER2-negative (n = 506) |
HER2-zero (n = 230) |
HER2-low (n = 276) |
p value | HER2-null H-score 0 (n = 121) |
HER2-ultralow H-score 1-120 (n = 109) |
p value | |
|---|---|---|---|---|---|---|---|
| Histological type (%) | |||||||
| IDC | 475 (93.9) | 212 (92.1) | 262 (95.6) | 0.029# | 112 (92.5) | 100 (91.7) | 0.973# |
| ILC | 22 (4.3) | 10 (4.4) | 11 (4.0) | 5 (4.1) | 5 (5.0) | ||
| Other | 9 (1.8) | 8 (3.5) | 1 (0.4) | 4 (3.4) | 4 (3.3) | ||
| Histological grade (%) | |||||||
| 1 | 10 (2.0) | 7 (3.1) | 3 (1.1) | 0.025# | 5 (4.2) | 2 (4.9) | 0.179# |
| 2 | 278 (54.9) | 113 (49.3) | 165 (60.2) | 53 (43.8) | 60 (55.0) | ||
| 3 | 218 (43.1) | 109 (47.6) | 106 (38.7) | 63 (52.0) | 47 (43.1) | ||
| TNM staging group (%) | |||||||
| I | 14 (2.8) | 4 (1.8) | 10 (3.7) | 0.24# | 3 (2.5) | 1 (0.9) | 0.436# |
| II | 252 (49.8) | 109 (47.6) | 141 (51.4) | 54 (44.6) | 56 (51.4) | ||
| III | 240 (47.4) | 116 (50.6) | 123 (44.9) | 64 (52.9) | 52 (47.7) | ||
| Menopausal status (%) | |||||||
| Premenopausal | 221 (43.7) | 100 (43.7) | 119 (43.4) | 0.99# | 63 (52.0) | 70 (64.2) | 0.044# |
| Postmenopausal | 283 (55.9) | 128 (55.9) | 154 (56.2) | 58 (48.0) | 38 (34.8) | ||
| Male breast cancer | 2 (0.4) | 1 (0.4) | 1 (0.4) | 0 (0) | 1 (1.0) | ||
| Hormone receptor (%) | |||||||
| Positive | 324 (64) | 130 (56.2) | 194 (70.3) | 0.0013# | 53 (43.8) | 77 (70.6) | < 0.001# |
| Negative | 182 (36) | 100 (43.8) | 82 (29.7) | 68 (56.2) | 32 (29.4) | ||
| RCB (%) | |||||||
| 0 | 92 (18.2) | 50 (21.7) | 42 (15.2) | 0.031# | 35 (29.0) | 15 (13.8) | 0.002# |
| I | 39 (7.7) | 16 (7.0) | 23 (8.4) | 9 (7.4) | 7 (6.4) | ||
| II | 212 (41.9) | 101 (43.9) | 111 (40.2) | 51 (42.1) | 50 (45.8) | ||
| III | 160 (31.6) | 62 (27.0) | 98 (35.5) | 25 (20.7) | 37 (34.0) | ||
| missing | 3 (0.6) | 1 (0.4) | 2 (0.7) | 1 (0.8) | 0 (0) | ||
| H-score, median | 20 | 0.00 | 0.40 | < 0.001* | 0.00 | 25 | < 0.0001* |
IC NOS, invasive carcinoma not-otherwise specified; TNM, tumor, node, metastasis; RCB, residual cancer burden
#Chi-square; *Mann-Whitney